Carbon Dioxide: Garden in
a Bottle
Purpose
- To demonstrate carbon dioxide is essential for plant growth.
- To learn that carbon dioxide is only one of many limiting
factors of plant growth.
Overview
The class will grow maize plants in a closed system under ambient
(unchanged) and decreased CO2 conditions. The amount CO2
available to plants is determined by the volume of the plastic bottle
in which the plants are cultivated. Decreased CO2 concentrations
are established by placing sodium hydroxide (NaOH), which absorbs CO2,
into the bottle before closing it. Students will evaluate the
impacts of decreased CO2 concetration on maize growth by making
observations and measurements on plant size, leaf color and change in
biomass.
Essential Questions
Where and how is the CO2 stored in the plant body?
Sub-Questions
How much CO2 does the air contain?
How does lower CO2 concentration in the air affect plant growth?
How is carbon dioxide a limiting factor to plant growth?
How does CO2 from the air get into the cells of plant leaves?
Do plant roots also need CO2?
Student Outcomes
- Students will understand how to formulate a reasonable hypothesis
- Students will know how to set up a simple biological experiment using maize plants
- Students will gain skills in scientific observation
- Students will learn to interpret experimental results
Science Concepts
- Formulating hypotehsis
- Testing hypothesis with experiment
- Planning and perfomrance of the experiment
- Presentation of the results and their interpretation
Time
Approximate total amount of time necessary for the experiment is 23-27
days. There can be slight variation in duration of each part of the
experiment due to differences in local conditions.
- Germination:
- Preparation for seed germination 1-2 class periods
- During germination, water daily and record germination progress– 10 minutes per day for 7 days.
- Cultivation:
- Preparation of the experimental system and planting 1-2 class periods
- During cultivation, water daily and record plants growth factors- 10 minutes per day for 14 days.
- Harvest:
- Preparation of the plants for drying 1 class period
- Drying:
- Place plants in drying oven for 8-12 hours at 90°C
- Evaluation/Interpretation:
- Record final results, review hypothesis, answer essential questions 1-2 class periods
Advanced Middle School & High School